TY - BOOK AU - Ahmed Moustafa Elbadrawy AU - Asmaa Youssif Harhash , AU - Mohamed Riad Farid , TI - Influence of different modes of light emitting diodes (LED) on surface hardness and color stability of contemporary restoratives / PY - 2017/// CY - Cairo : PB - Ahmed Moustafa Elbadrawy , KW - Color Stability KW - Light Emitting Diodes (LED) KW - Surface Hardness N1 - Thesis (M.Sc.) - Cairo University - Faculty of Oral and Dental Medicine - Department of Operative Dentistry; Issued also as CD N2 - The present in-vitro study was designed to evaluate the effect of using three different curing modes (low intensity mode, high intensity mode, and soft start mode) and two mouth rinses (Hixiteol, Listerine) on some surface characteristics of two restorative materials (one nanofilled resin composite restorative material, one nanofilled resin modified glass Ionomer restorative material( A total of 180 disk- shaped specimens were prepared in a specially prepared Teflon mold. The light was applied perpendicular on the specimen. After polymerization, the upper surfaces of the specimens was finished with silicone carbide paper. The specimens of each tested material were then divided into three groups according to polymerization mode using a LED device, 30 specimens each (10 specimens for each polymerization mode). Group A(LL) was light cured with low intensity mode, group B(Lh) was light cured with High intensity mode and group C(Ls) was cured with Soft start mode. Then each group was further subdivided according to the storage in the different solutions into three subgroups, distilled water for 2 weeks (R0 control subgroup), Hexiteol mouth wash (R1 subgroup) and Listerine mouth wash (R2 subgroup), for 12 hours at 37{u00B0}C. Specimens were tested using Vickersmicrohardness tester with a definite load application(HV 50 g).The specimens were incubated in distilled water at 37{u00B0}C for 24 hours. Then, the baseline color values of each specimen were measuredwith a spectrophotometer. Each subgroup were stored in 20 mL of one of the mouth rinses for 12 hours. Specimens were kept at 37{u00B0}C throughout the study, and test solutions were shaken every 3 hours to provide homogeneity. At the end of the testperiod, the specimens were removed and submerged in distilled water. After the immersion, the color values of each specimen were remeasured. The data obtained and statistically analyzed ER -